Library District Week will begin today with a public hearing and conclude on Thursday with a vote. Commissioners might surprise everyone at that point and decide that temporary levies are just fine. It's more likely that they'll ask voters to create a district, either this November or in November 2014. In this instance, later is better than sooner.

Those who'd like to create a district argue that doing so will eliminate the need to seek temporary library levies, which is at the very least a hassle. They're right, though libraries are an easy sell: Voters overwhelmingly approved a three-year levy in May despite the lingering effects of the great recession.

That levy conveniently gives commissioners enough breathing room to defer a library-district vote until November 2014. Should that attempt fail, the county could seek another temporary levy the following May, which probably would pass with ease.

Voting on a district in November, then, isn't a do-or-die proposition. Sure, library money is tight, but times are tough throughout the state, in the private and public sectors alike.

Scheduling a vote this fall, meanwhile, could cause unintended problems. November's ballot is already groaning beneath the weight of the school bond and the lamentable arts tax. School officials, having made a mess of the last bond, need to convince skeptical voters this summer that they'll use the bond funds efficiently and maintain older buildings adequately. If they do make the case, the bond will be the one tax measure Portland voters really should approve this fall.

Multnomah County commissioners won't improve its chances by expanding the ballot with a library measure that can wait for a couple of years. How many frugal voters who'd otherwise support the school bond would back the library district instead? Why take the chance at all?

Another reason to delay is complexity. Swapping a succession of library levies for a permanent district sounds like a clean, simple operation, but it isn't. It has implications for other government entities, including the city of Portland, and waiting a couple of years will give the Legislature -- and perhaps voters -- a chance to wrestle with a contributing problem: property tax compression.

Oregon's tax limits squeeze collections on affected properties, of which there are many in Portland. Local option levies, like the one that supports Multnomah County's libraries, are squeezed first, followed by permanent rates, like those that support Portland, Multnomah County and ... library districts.

Leapfrogging from temporary levies to a permanent rate would reduce the vulnerability of county libraries to compression losses. But it also would siphon money from other taxing entities, including the city of Portland, which would lose millions of dollars a year.

Voters may conclude that the trade-off is a good one. Then again, given time, they might decide that the best option is to exempt local option levies entirely from the property tax limits that produce compression. The Legislature, which would have to refer such a change to voters, is likely to at least consider such a bill in 2013.